A look at US diplomatic security around the world

WASHINGTON (AP) — Thursday's knife attack on America's ambassador in Seoul was the first major case of violence involving a U.S. ambassador since the deadly siege in Benghazi, Libya, more than two years ago.

That's where similarities end. Whereas Libya remains engulfed in post-revolution chaos, torn between rival militias and terrorist organizations, South Korea is a U.S. ally and has a low crime rate. The U.S. security posture in each place is thus different.

Even in the safest places, ambassadors from the United States generally have greater security than their counterparts from other countries. In theory, an attack on a top U.S. official should not be allowed to happen.

But incidents invariably occur as officials serving in friendly and hostile countries come in daily contact with people who may pose risks. Eliminating those risks entirely would mean preventing diplomats from doing their jobs.

A look at what is done for the security of U.S. officials overseas:

___

HOST COUNTRY:

The State Department hasn't described the level of security that accompanied ambassador Mark Lippert to a breakfast meeting held by a Korean non-governmental group where, police say, a man with a long history of anti-American protests slashed Lippert's face and arm.

Lippert is hospitalized with deep gashes and damaged tendons and nerves.

At its most basic, the protection of diplomatic facilities and personnel is the responsibility of host nations. That can involve military, national guard or private security contractors.

South Korea's record in this regard had been strong.

Lippert is the first ambassador to be injured in a violent attack in modern history, authorities said. However, questions will be asked about how an assailant who narrowly missed a Japanese ambassador five years ago with a thrown piece of concrete was able to attack again.

___

U.S. DIPLOMATIC SECURITY:

Under international law, governments aren't supposed to deploy a military presence into countries hosting their embassies and diplomats. But the experience of various deadly attacks over the years dictated that the U.S. and other high-visibility nations augment their own security.

Since the mid-1980s, the U.S. Diplomatic Security Service has shared protection responsibilities. In addition to guarding facilities and serving on details, it conducts investigations, threat analysis, cybersecurity and counterterrorism operations.

Operating in more than 160 countries as well as in the United States for foreign diplomat protection, Diplomatic Security agents are trained in to use force if necessary. They carry arms and can make arrests.

Entrusted with protecting some 100,000 people, the service is stretched far and tends to operate in most instances on a smaller footprint than, say, a Secret Service detail traveling with the president. It also must take into account cultural factors and diplomatic objectives when contemplating the size of a mission.

Diplomatic Security also has an elite force of agents who train alongside Marines. They are usually reserved for high-threat posts more akin to Benghazi than Seoul, and high-profile visits or events.

___

MARINES:

Many American diplomatic compounds host Marine detachments, too. The Marines' primary responsibility is to protect classified information and sensitive equipment in the event of security breach.

Marines can and do use force, however, even if they aren't usually in charge of day-to-day protection duties in low-threat locations like South Korea.

In 2013, for example, agents and Marines teamed in fending off an attack involving a truck bomb, militants with suicide vests and rocket fire targeting the U.S. consulate in Herat, Afghanistan.

But the Marines work less beyond U.S. government grounds, focusing more on lobby entrances and reacting to fires, riots, demonstrations, evacuations and other emergencies.